Linux Audio

Check our new training course

Yocto / OpenEmbedded training

Feb 10-13, 2025
Register
Loading...
v5.9
  1/*
  2 * arch/sh/mm/cache-sh4.c
  3 *
  4 * Copyright (C) 1999, 2000, 2002  Niibe Yutaka
  5 * Copyright (C) 2001 - 2009  Paul Mundt
  6 * Copyright (C) 2003  Richard Curnow
  7 * Copyright (c) 2007 STMicroelectronics (R&D) Ltd.
  8 *
  9 * This file is subject to the terms and conditions of the GNU General Public
 10 * License.  See the file "COPYING" in the main directory of this archive
 11 * for more details.
 12 */
 13#include <linux/init.h>
 14#include <linux/mm.h>
 15#include <linux/io.h>
 16#include <linux/mutex.h>
 17#include <linux/fs.h>
 18#include <linux/highmem.h>
 
 19#include <asm/mmu_context.h>
 20#include <asm/cache_insns.h>
 21#include <asm/cacheflush.h>
 22
 23/*
 24 * The maximum number of pages we support up to when doing ranged dcache
 25 * flushing. Anything exceeding this will simply flush the dcache in its
 26 * entirety.
 27 */
 28#define MAX_ICACHE_PAGES	32
 29
 30static void __flush_cache_one(unsigned long addr, unsigned long phys,
 31			       unsigned long exec_offset);
 32
 33/*
 34 * Write back the range of D-cache, and purge the I-cache.
 35 *
 36 * Called from kernel/module.c:sys_init_module and routine for a.out format,
 37 * signal handler code and kprobes code
 38 */
 39static void sh4_flush_icache_range(void *args)
 40{
 41	struct flusher_data *data = args;
 42	unsigned long start, end;
 43	unsigned long flags, v;
 44	int i;
 45
 46	start = data->addr1;
 47	end = data->addr2;
 48
 49	/* If there are too many pages then just blow away the caches */
 50	if (((end - start) >> PAGE_SHIFT) >= MAX_ICACHE_PAGES) {
 51		local_flush_cache_all(NULL);
 52		return;
 53	}
 54
 55	/*
 56	 * Selectively flush d-cache then invalidate the i-cache.
 57	 * This is inefficient, so only use this for small ranges.
 58	 */
 59	start &= ~(L1_CACHE_BYTES-1);
 60	end += L1_CACHE_BYTES-1;
 61	end &= ~(L1_CACHE_BYTES-1);
 62
 63	local_irq_save(flags);
 64	jump_to_uncached();
 65
 66	for (v = start; v < end; v += L1_CACHE_BYTES) {
 67		unsigned long icacheaddr;
 68		int j, n;
 69
 70		__ocbwb(v);
 71
 72		icacheaddr = CACHE_IC_ADDRESS_ARRAY | (v &
 73				cpu_data->icache.entry_mask);
 74
 75		/* Clear i-cache line valid-bit */
 76		n = boot_cpu_data.icache.n_aliases;
 77		for (i = 0; i < cpu_data->icache.ways; i++) {
 78			for (j = 0; j < n; j++)
 79				__raw_writel(0, icacheaddr + (j * PAGE_SIZE));
 80			icacheaddr += cpu_data->icache.way_incr;
 81		}
 82	}
 83
 84	back_to_cached();
 85	local_irq_restore(flags);
 86}
 87
 88static inline void flush_cache_one(unsigned long start, unsigned long phys)
 89{
 90	unsigned long flags, exec_offset = 0;
 91
 92	/*
 93	 * All types of SH-4 require PC to be uncached to operate on the I-cache.
 94	 * Some types of SH-4 require PC to be uncached to operate on the D-cache.
 95	 */
 96	if ((boot_cpu_data.flags & CPU_HAS_P2_FLUSH_BUG) ||
 97	    (start < CACHE_OC_ADDRESS_ARRAY))
 98		exec_offset = cached_to_uncached;
 99
100	local_irq_save(flags);
101	__flush_cache_one(start, phys, exec_offset);
102	local_irq_restore(flags);
103}
104
105/*
106 * Write back & invalidate the D-cache of the page.
107 * (To avoid "alias" issues)
108 */
109static void sh4_flush_dcache_page(void *arg)
110{
111	struct page *page = arg;
112	unsigned long addr = (unsigned long)page_address(page);
113#ifndef CONFIG_SMP
114	struct address_space *mapping = page_mapping_file(page);
115
116	if (mapping && !mapping_mapped(mapping))
117		clear_bit(PG_dcache_clean, &page->flags);
118	else
119#endif
120		flush_cache_one(CACHE_OC_ADDRESS_ARRAY |
121				(addr & shm_align_mask), page_to_phys(page));
 
 
 
 
 
 
 
 
 
 
 
122
123	wmb();
124}
125
126/* TODO: Selective icache invalidation through IC address array.. */
127static void flush_icache_all(void)
128{
129	unsigned long flags, ccr;
130
131	local_irq_save(flags);
132	jump_to_uncached();
133
134	/* Flush I-cache */
135	ccr = __raw_readl(SH_CCR);
136	ccr |= CCR_CACHE_ICI;
137	__raw_writel(ccr, SH_CCR);
138
139	/*
140	 * back_to_cached() will take care of the barrier for us, don't add
141	 * another one!
142	 */
143
144	back_to_cached();
145	local_irq_restore(flags);
146}
147
148static void flush_dcache_all(void)
149{
150	unsigned long addr, end_addr, entry_offset;
151
152	end_addr = CACHE_OC_ADDRESS_ARRAY +
153		(current_cpu_data.dcache.sets <<
154		 current_cpu_data.dcache.entry_shift) *
155			current_cpu_data.dcache.ways;
156
157	entry_offset = 1 << current_cpu_data.dcache.entry_shift;
158
159	for (addr = CACHE_OC_ADDRESS_ARRAY; addr < end_addr; ) {
160		__raw_writel(0, addr); addr += entry_offset;
161		__raw_writel(0, addr); addr += entry_offset;
162		__raw_writel(0, addr); addr += entry_offset;
163		__raw_writel(0, addr); addr += entry_offset;
164		__raw_writel(0, addr); addr += entry_offset;
165		__raw_writel(0, addr); addr += entry_offset;
166		__raw_writel(0, addr); addr += entry_offset;
167		__raw_writel(0, addr); addr += entry_offset;
168	}
169}
170
171static void sh4_flush_cache_all(void *unused)
172{
173	flush_dcache_all();
174	flush_icache_all();
175}
176
177/*
178 * Note : (RPC) since the caches are physically tagged, the only point
179 * of flush_cache_mm for SH-4 is to get rid of aliases from the
180 * D-cache.  The assumption elsewhere, e.g. flush_cache_range, is that
181 * lines can stay resident so long as the virtual address they were
182 * accessed with (hence cache set) is in accord with the physical
183 * address (i.e. tag).  It's no different here.
184 *
185 * Caller takes mm->mmap_lock.
186 */
187static void sh4_flush_cache_mm(void *arg)
188{
189	struct mm_struct *mm = arg;
190
191	if (cpu_context(smp_processor_id(), mm) == NO_CONTEXT)
192		return;
193
194	flush_dcache_all();
195}
196
197/*
198 * Write back and invalidate I/D-caches for the page.
199 *
200 * ADDR: Virtual Address (U0 address)
201 * PFN: Physical page number
202 */
203static void sh4_flush_cache_page(void *args)
204{
205	struct flusher_data *data = args;
206	struct vm_area_struct *vma;
207	struct page *page;
208	unsigned long address, pfn, phys;
209	int map_coherent = 0;
210	pmd_t *pmd;
211	pte_t *pte;
212	void *vaddr;
213
214	vma = data->vma;
215	address = data->addr1 & PAGE_MASK;
216	pfn = data->addr2;
217	phys = pfn << PAGE_SHIFT;
218	page = pfn_to_page(pfn);
219
220	if (cpu_context(smp_processor_id(), vma->vm_mm) == NO_CONTEXT)
221		return;
222
223	pmd = pmd_off(vma->vm_mm, address);
224	pte = pte_offset_kernel(pmd, address);
225
226	/* If the page isn't present, there is nothing to do here. */
227	if (!(pte_val(*pte) & _PAGE_PRESENT))
228		return;
229
230	if ((vma->vm_mm == current->active_mm))
231		vaddr = NULL;
232	else {
233		/*
234		 * Use kmap_coherent or kmap_atomic to do flushes for
235		 * another ASID than the current one.
236		 */
237		map_coherent = (current_cpu_data.dcache.n_aliases &&
238			test_bit(PG_dcache_clean, &page->flags) &&
239			page_mapcount(page));
240		if (map_coherent)
241			vaddr = kmap_coherent(page, address);
242		else
243			vaddr = kmap_atomic(page);
244
245		address = (unsigned long)vaddr;
246	}
247
248	flush_cache_one(CACHE_OC_ADDRESS_ARRAY |
249			(address & shm_align_mask), phys);
250
251	if (vma->vm_flags & VM_EXEC)
252		flush_icache_all();
253
254	if (vaddr) {
255		if (map_coherent)
256			kunmap_coherent(vaddr);
257		else
258			kunmap_atomic(vaddr);
259	}
260}
261
262/*
263 * Write back and invalidate D-caches.
264 *
265 * START, END: Virtual Address (U0 address)
266 *
267 * NOTE: We need to flush the _physical_ page entry.
268 * Flushing the cache lines for U0 only isn't enough.
269 * We need to flush for P1 too, which may contain aliases.
270 */
271static void sh4_flush_cache_range(void *args)
272{
273	struct flusher_data *data = args;
274	struct vm_area_struct *vma;
275	unsigned long start, end;
276
277	vma = data->vma;
278	start = data->addr1;
279	end = data->addr2;
280
281	if (cpu_context(smp_processor_id(), vma->vm_mm) == NO_CONTEXT)
282		return;
283
284	/*
285	 * If cache is only 4k-per-way, there are never any 'aliases'.  Since
286	 * the cache is physically tagged, the data can just be left in there.
287	 */
288	if (boot_cpu_data.dcache.n_aliases == 0)
289		return;
290
291	flush_dcache_all();
292
293	if (vma->vm_flags & VM_EXEC)
294		flush_icache_all();
295}
296
297/**
298 * __flush_cache_one
299 *
300 * @addr:  address in memory mapped cache array
301 * @phys:  P1 address to flush (has to match tags if addr has 'A' bit
302 *         set i.e. associative write)
303 * @exec_offset: set to 0x20000000 if flush has to be executed from P2
304 *               region else 0x0
305 *
306 * The offset into the cache array implied by 'addr' selects the
307 * 'colour' of the virtual address range that will be flushed.  The
308 * operation (purge/write-back) is selected by the lower 2 bits of
309 * 'phys'.
310 */
311static void __flush_cache_one(unsigned long addr, unsigned long phys,
312			       unsigned long exec_offset)
313{
314	int way_count;
315	unsigned long base_addr = addr;
316	struct cache_info *dcache;
317	unsigned long way_incr;
318	unsigned long a, ea, p;
319	unsigned long temp_pc;
320
321	dcache = &boot_cpu_data.dcache;
322	/* Write this way for better assembly. */
323	way_count = dcache->ways;
324	way_incr = dcache->way_incr;
325
326	/*
327	 * Apply exec_offset (i.e. branch to P2 if required.).
328	 *
329	 * FIXME:
330	 *
331	 *	If I write "=r" for the (temp_pc), it puts this in r6 hence
332	 *	trashing exec_offset before it's been added on - why?  Hence
333	 *	"=&r" as a 'workaround'
334	 */
335	asm volatile("mov.l 1f, %0\n\t"
336		     "add   %1, %0\n\t"
337		     "jmp   @%0\n\t"
338		     "nop\n\t"
339		     ".balign 4\n\t"
340		     "1:  .long 2f\n\t"
341		     "2:\n" : "=&r" (temp_pc) : "r" (exec_offset));
342
343	/*
344	 * We know there will be >=1 iteration, so write as do-while to avoid
345	 * pointless nead-of-loop check for 0 iterations.
346	 */
347	do {
348		ea = base_addr + PAGE_SIZE;
349		a = base_addr;
350		p = phys;
351
352		do {
353			*(volatile unsigned long *)a = p;
354			/*
355			 * Next line: intentionally not p+32, saves an add, p
356			 * will do since only the cache tag bits need to
357			 * match.
358			 */
359			*(volatile unsigned long *)(a+32) = p;
360			a += 64;
361			p += 64;
362		} while (a < ea);
363
364		base_addr += way_incr;
365	} while (--way_count != 0);
366}
367
368extern void __weak sh4__flush_region_init(void);
369
370/*
371 * SH-4 has virtually indexed and physically tagged cache.
372 */
373void __init sh4_cache_init(void)
374{
375	printk("PVR=%08x CVR=%08x PRR=%08x\n",
376		__raw_readl(CCN_PVR),
377		__raw_readl(CCN_CVR),
378		__raw_readl(CCN_PRR));
379
380	local_flush_icache_range	= sh4_flush_icache_range;
381	local_flush_dcache_page		= sh4_flush_dcache_page;
382	local_flush_cache_all		= sh4_flush_cache_all;
383	local_flush_cache_mm		= sh4_flush_cache_mm;
384	local_flush_cache_dup_mm	= sh4_flush_cache_mm;
385	local_flush_cache_page		= sh4_flush_cache_page;
386	local_flush_cache_range		= sh4_flush_cache_range;
387
388	sh4__flush_region_init();
389}
v6.9.4
  1/*
  2 * arch/sh/mm/cache-sh4.c
  3 *
  4 * Copyright (C) 1999, 2000, 2002  Niibe Yutaka
  5 * Copyright (C) 2001 - 2009  Paul Mundt
  6 * Copyright (C) 2003  Richard Curnow
  7 * Copyright (c) 2007 STMicroelectronics (R&D) Ltd.
  8 *
  9 * This file is subject to the terms and conditions of the GNU General Public
 10 * License.  See the file "COPYING" in the main directory of this archive
 11 * for more details.
 12 */
 13#include <linux/init.h>
 14#include <linux/mm.h>
 15#include <linux/io.h>
 16#include <linux/mutex.h>
 17#include <linux/fs.h>
 18#include <linux/highmem.h>
 19#include <linux/pagemap.h>
 20#include <asm/mmu_context.h>
 21#include <asm/cache_insns.h>
 22#include <asm/cacheflush.h>
 23
 24/*
 25 * The maximum number of pages we support up to when doing ranged dcache
 26 * flushing. Anything exceeding this will simply flush the dcache in its
 27 * entirety.
 28 */
 29#define MAX_ICACHE_PAGES	32
 30
 31static void __flush_cache_one(unsigned long addr, unsigned long phys,
 32			       unsigned long exec_offset);
 33
 34/*
 35 * Write back the range of D-cache, and purge the I-cache.
 36 *
 37 * Called from kernel/module.c:sys_init_module and routine for a.out format,
 38 * signal handler code and kprobes code
 39 */
 40static void sh4_flush_icache_range(void *args)
 41{
 42	struct flusher_data *data = args;
 43	unsigned long start, end;
 44	unsigned long flags, v;
 45	int i;
 46
 47	start = data->addr1;
 48	end = data->addr2;
 49
 50	/* If there are too many pages then just blow away the caches */
 51	if (((end - start) >> PAGE_SHIFT) >= MAX_ICACHE_PAGES) {
 52		local_flush_cache_all(NULL);
 53		return;
 54	}
 55
 56	/*
 57	 * Selectively flush d-cache then invalidate the i-cache.
 58	 * This is inefficient, so only use this for small ranges.
 59	 */
 60	start &= ~(L1_CACHE_BYTES-1);
 61	end += L1_CACHE_BYTES-1;
 62	end &= ~(L1_CACHE_BYTES-1);
 63
 64	local_irq_save(flags);
 65	jump_to_uncached();
 66
 67	for (v = start; v < end; v += L1_CACHE_BYTES) {
 68		unsigned long icacheaddr;
 69		int j, n;
 70
 71		__ocbwb(v);
 72
 73		icacheaddr = CACHE_IC_ADDRESS_ARRAY | (v &
 74				cpu_data->icache.entry_mask);
 75
 76		/* Clear i-cache line valid-bit */
 77		n = boot_cpu_data.icache.n_aliases;
 78		for (i = 0; i < cpu_data->icache.ways; i++) {
 79			for (j = 0; j < n; j++)
 80				__raw_writel(0, icacheaddr + (j * PAGE_SIZE));
 81			icacheaddr += cpu_data->icache.way_incr;
 82		}
 83	}
 84
 85	back_to_cached();
 86	local_irq_restore(flags);
 87}
 88
 89static inline void flush_cache_one(unsigned long start, unsigned long phys)
 90{
 91	unsigned long flags, exec_offset = 0;
 92
 93	/*
 94	 * All types of SH-4 require PC to be uncached to operate on the I-cache.
 95	 * Some types of SH-4 require PC to be uncached to operate on the D-cache.
 96	 */
 97	if ((boot_cpu_data.flags & CPU_HAS_P2_FLUSH_BUG) ||
 98	    (start < CACHE_OC_ADDRESS_ARRAY))
 99		exec_offset = cached_to_uncached;
100
101	local_irq_save(flags);
102	__flush_cache_one(start, phys, exec_offset);
103	local_irq_restore(flags);
104}
105
106/*
107 * Write back & invalidate the D-cache of the page.
108 * (To avoid "alias" issues)
109 */
110static void sh4_flush_dcache_folio(void *arg)
111{
112	struct folio *folio = arg;
 
113#ifndef CONFIG_SMP
114	struct address_space *mapping = folio_flush_mapping(folio);
115
116	if (mapping && !mapping_mapped(mapping))
117		clear_bit(PG_dcache_clean, &folio->flags);
118	else
119#endif
120	{
121		unsigned long pfn = folio_pfn(folio);
122		unsigned long addr = (unsigned long)folio_address(folio);
123		unsigned int i, nr = folio_nr_pages(folio);
124
125		for (i = 0; i < nr; i++) {
126			flush_cache_one(CACHE_OC_ADDRESS_ARRAY |
127						(addr & shm_align_mask),
128					pfn * PAGE_SIZE);
129			addr += PAGE_SIZE;
130			pfn++;
131		}
132	}
133
134	wmb();
135}
136
137/* TODO: Selective icache invalidation through IC address array.. */
138static void flush_icache_all(void)
139{
140	unsigned long flags, ccr;
141
142	local_irq_save(flags);
143	jump_to_uncached();
144
145	/* Flush I-cache */
146	ccr = __raw_readl(SH_CCR);
147	ccr |= CCR_CACHE_ICI;
148	__raw_writel(ccr, SH_CCR);
149
150	/*
151	 * back_to_cached() will take care of the barrier for us, don't add
152	 * another one!
153	 */
154
155	back_to_cached();
156	local_irq_restore(flags);
157}
158
159static void flush_dcache_all(void)
160{
161	unsigned long addr, end_addr, entry_offset;
162
163	end_addr = CACHE_OC_ADDRESS_ARRAY +
164		(current_cpu_data.dcache.sets <<
165		 current_cpu_data.dcache.entry_shift) *
166			current_cpu_data.dcache.ways;
167
168	entry_offset = 1 << current_cpu_data.dcache.entry_shift;
169
170	for (addr = CACHE_OC_ADDRESS_ARRAY; addr < end_addr; ) {
171		__raw_writel(0, addr); addr += entry_offset;
172		__raw_writel(0, addr); addr += entry_offset;
173		__raw_writel(0, addr); addr += entry_offset;
174		__raw_writel(0, addr); addr += entry_offset;
175		__raw_writel(0, addr); addr += entry_offset;
176		__raw_writel(0, addr); addr += entry_offset;
177		__raw_writel(0, addr); addr += entry_offset;
178		__raw_writel(0, addr); addr += entry_offset;
179	}
180}
181
182static void sh4_flush_cache_all(void *unused)
183{
184	flush_dcache_all();
185	flush_icache_all();
186}
187
188/*
189 * Note : (RPC) since the caches are physically tagged, the only point
190 * of flush_cache_mm for SH-4 is to get rid of aliases from the
191 * D-cache.  The assumption elsewhere, e.g. flush_cache_range, is that
192 * lines can stay resident so long as the virtual address they were
193 * accessed with (hence cache set) is in accord with the physical
194 * address (i.e. tag).  It's no different here.
195 *
196 * Caller takes mm->mmap_lock.
197 */
198static void sh4_flush_cache_mm(void *arg)
199{
200	struct mm_struct *mm = arg;
201
202	if (cpu_context(smp_processor_id(), mm) == NO_CONTEXT)
203		return;
204
205	flush_dcache_all();
206}
207
208/*
209 * Write back and invalidate I/D-caches for the page.
210 *
211 * ADDR: Virtual Address (U0 address)
212 * PFN: Physical page number
213 */
214static void sh4_flush_cache_page(void *args)
215{
216	struct flusher_data *data = args;
217	struct vm_area_struct *vma;
218	struct page *page;
219	unsigned long address, pfn, phys;
220	int map_coherent = 0;
221	pmd_t *pmd;
222	pte_t *pte;
223	void *vaddr;
224
225	vma = data->vma;
226	address = data->addr1 & PAGE_MASK;
227	pfn = data->addr2;
228	phys = pfn << PAGE_SHIFT;
229	page = pfn_to_page(pfn);
230
231	if (cpu_context(smp_processor_id(), vma->vm_mm) == NO_CONTEXT)
232		return;
233
234	pmd = pmd_off(vma->vm_mm, address);
235	pte = pte_offset_kernel(pmd, address);
236
237	/* If the page isn't present, there is nothing to do here. */
238	if (!(pte_val(*pte) & _PAGE_PRESENT))
239		return;
240
241	if ((vma->vm_mm == current->active_mm))
242		vaddr = NULL;
243	else {
244		/*
245		 * Use kmap_coherent or kmap_atomic to do flushes for
246		 * another ASID than the current one.
247		 */
248		map_coherent = (current_cpu_data.dcache.n_aliases &&
249			test_bit(PG_dcache_clean, &page->flags) &&
250			page_mapcount(page));
251		if (map_coherent)
252			vaddr = kmap_coherent(page, address);
253		else
254			vaddr = kmap_atomic(page);
255
256		address = (unsigned long)vaddr;
257	}
258
259	flush_cache_one(CACHE_OC_ADDRESS_ARRAY |
260			(address & shm_align_mask), phys);
261
262	if (vma->vm_flags & VM_EXEC)
263		flush_icache_all();
264
265	if (vaddr) {
266		if (map_coherent)
267			kunmap_coherent(vaddr);
268		else
269			kunmap_atomic(vaddr);
270	}
271}
272
273/*
274 * Write back and invalidate D-caches.
275 *
276 * START, END: Virtual Address (U0 address)
277 *
278 * NOTE: We need to flush the _physical_ page entry.
279 * Flushing the cache lines for U0 only isn't enough.
280 * We need to flush for P1 too, which may contain aliases.
281 */
282static void sh4_flush_cache_range(void *args)
283{
284	struct flusher_data *data = args;
285	struct vm_area_struct *vma;
286	unsigned long start, end;
287
288	vma = data->vma;
289	start = data->addr1;
290	end = data->addr2;
291
292	if (cpu_context(smp_processor_id(), vma->vm_mm) == NO_CONTEXT)
293		return;
294
295	/*
296	 * If cache is only 4k-per-way, there are never any 'aliases'.  Since
297	 * the cache is physically tagged, the data can just be left in there.
298	 */
299	if (boot_cpu_data.dcache.n_aliases == 0)
300		return;
301
302	flush_dcache_all();
303
304	if (vma->vm_flags & VM_EXEC)
305		flush_icache_all();
306}
307
308/**
309 * __flush_cache_one
310 *
311 * @addr:  address in memory mapped cache array
312 * @phys:  P1 address to flush (has to match tags if addr has 'A' bit
313 *         set i.e. associative write)
314 * @exec_offset: set to 0x20000000 if flush has to be executed from P2
315 *               region else 0x0
316 *
317 * The offset into the cache array implied by 'addr' selects the
318 * 'colour' of the virtual address range that will be flushed.  The
319 * operation (purge/write-back) is selected by the lower 2 bits of
320 * 'phys'.
321 */
322static void __flush_cache_one(unsigned long addr, unsigned long phys,
323			       unsigned long exec_offset)
324{
325	int way_count;
326	unsigned long base_addr = addr;
327	struct cache_info *dcache;
328	unsigned long way_incr;
329	unsigned long a, ea, p;
330	unsigned long temp_pc;
331
332	dcache = &boot_cpu_data.dcache;
333	/* Write this way for better assembly. */
334	way_count = dcache->ways;
335	way_incr = dcache->way_incr;
336
337	/*
338	 * Apply exec_offset (i.e. branch to P2 if required.).
339	 *
340	 * FIXME:
341	 *
342	 *	If I write "=r" for the (temp_pc), it puts this in r6 hence
343	 *	trashing exec_offset before it's been added on - why?  Hence
344	 *	"=&r" as a 'workaround'
345	 */
346	asm volatile("mov.l 1f, %0\n\t"
347		     "add   %1, %0\n\t"
348		     "jmp   @%0\n\t"
349		     "nop\n\t"
350		     ".balign 4\n\t"
351		     "1:  .long 2f\n\t"
352		     "2:\n" : "=&r" (temp_pc) : "r" (exec_offset));
353
354	/*
355	 * We know there will be >=1 iteration, so write as do-while to avoid
356	 * pointless nead-of-loop check for 0 iterations.
357	 */
358	do {
359		ea = base_addr + PAGE_SIZE;
360		a = base_addr;
361		p = phys;
362
363		do {
364			*(volatile unsigned long *)a = p;
365			/*
366			 * Next line: intentionally not p+32, saves an add, p
367			 * will do since only the cache tag bits need to
368			 * match.
369			 */
370			*(volatile unsigned long *)(a+32) = p;
371			a += 64;
372			p += 64;
373		} while (a < ea);
374
375		base_addr += way_incr;
376	} while (--way_count != 0);
377}
378
379extern void __weak sh4__flush_region_init(void);
380
381/*
382 * SH-4 has virtually indexed and physically tagged cache.
383 */
384void __init sh4_cache_init(void)
385{
386	printk("PVR=%08x CVR=%08x PRR=%08x\n",
387		__raw_readl(CCN_PVR),
388		__raw_readl(CCN_CVR),
389		__raw_readl(CCN_PRR));
390
391	local_flush_icache_range	= sh4_flush_icache_range;
392	local_flush_dcache_folio	= sh4_flush_dcache_folio;
393	local_flush_cache_all		= sh4_flush_cache_all;
394	local_flush_cache_mm		= sh4_flush_cache_mm;
395	local_flush_cache_dup_mm	= sh4_flush_cache_mm;
396	local_flush_cache_page		= sh4_flush_cache_page;
397	local_flush_cache_range		= sh4_flush_cache_range;
398
399	sh4__flush_region_init();
400}